Electrical-pressure indicator



(No Model.) 8 0. B. SHALLENBER-GER.

ELECTRICAL PRESSURE, INDICATOR. -No. 380,944. Patented Apr. 10, 1888.

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OLIVER B. SHALLENBERGER, OF ROCHESTER, ASSIGNOR TO THE WESTING- HOUSE ELECTRIC COMPANY, OF PITTSBURG, PENNSYLVANIA.

ELECTRICAL PRESSURE ENDECATQ.

SPECIFICATION forming part of Letters Patent No. 380,944, dated April 10, 1888.

Application filed September 1, 1887. Serial No. 248,468. (No model.)

To aZZ whom it may concern.-

Be it known that I, OLIVER B. SHALLEN- BERGER, a citizen of the United States, residing in Rochester, in the county of Beaver and State of Pennsylvania, have invented certain new and useful Improvements in Electrical-Pressure Indicators,of which the following is a specification.

The invention relates to the class of appara- IO tus employed for indicating at any time the current upon an electric circuit, and the object is to provide convenient means for determining and regulating at a central station the potential upon the worlocircuit.

r 5 Theinvention consists,general1y,in deriving from the main circuit currents havinga potential directly dependent upon the difference of potential at the terminals of the generator and currents upon a second circuit having a potenzo tial dependent upon or affected by the loss or drop upon the lines when that loss is enough to cause an appreciable loss upon the workcircuit. The currents thus derived are balanced against or caused to oppose each other,

and the resultant indicates the difference of potential upon the work-circuit.

In another application filed by me April 23, 1887, Serial N 0. 235,838, there is described an organization of apparatus in some respects re- 0 sembling that herein shown.

The invention will be described more particularly in connection with the accompanying drawing, which is a diagram illustrating an organization of circuits for carrying out the 5 invention.

Referring to the figure, L L represent conductors leading from any suitable source of electricity to a work-circuit, as indicated in dottedlines. The work-circuit is represented 0 at D D translating devices d (1 being connected therein in multiple arc with each other.

At or near the central station conductors l 2 and 3 4 lead from the lines L and L respectivel y, through a solenoid, c. A second solen' 5 oid, b, wound differentially with respect to the solenoid c, is connected in a branch circuit, 5 6, derived from the conductors l 4. These two solenoids are thus traversed by similar currents derived from the conductors L and L". In circuit with one of the coils-C there is included a metallic resistance, R, and

preferably, also, an adjustable resistance, r.

In circuit with the other coil, 7), there are in serted carbon resistances,which may be incandescent electric lamps Z Z. This organization is somewhat similar to that described in a patent issued to Philip Lange, May 3, 1887,

N o. 362A51.

The resistances in the two circuits are equal under the influence of currents of a certain potential. If the potential is kept constant, a galvanometer-needle, N S,and indicator 1*, applied to a plate, F, will not show any deflection; but an increase of potential will send a stronger current through both circuits. This will reduce the resistance of the carbon circuit, including the solenoid b,without decreasing the resistance of the metallic circuit, including the coils 0. Thus more current will pass through the carbon side of theinstrument, and a corresponding deflection of the needle is occasioned. A decrease in the potential will deflect the needle in the opposite direction.

Applied to the device thus organized is a coil, a,which is included in the direct circuit of the conductor L and therefore this coil is traversed by the entire current passing to the work-circuit D D. The coil a is wound in the direction opposite to the coil 1', and the coils I) and c are so proportioned with referonce to the coil a as to maintain a balance when no current is flowing in the coil a, and the normal difference of potential exists at the terminals of the generator. When very little current flows through the main-line circuit L 8 5 L, the difference of potential at the generator is practically the same as at the lamps or translating devices d d,- but as the current increases, the loss in the line increases proportionately, and hence to preserve the normal 0 difference of potential at the translating devices the difference of potential at the generator must be increased. This would tend to throw the indicator out of balance, carrying the pointer F in a given direction-say to Ward the right hand-but for the action of the coil a,which, being traversed by the main current, tends to restore the equilibrium. If the loss in the main-line circuit amounts to, say, ten per cent. of the useful work at a full load, then the difference of potential at the generator should be ten per cent. higher than when the load isvery small. If, therefore, the coil a has an effect equal to one-eleventh of the resultant of the coils b and c, the balance will still be maintained. In this manner the indicator will serve to show when the difference of potential at the translating devices is at its required value.

I claim as my in vention 1. In an indicator for electric circuits, the combination of two opposing coils,the one connected in a shunt-circuit with the translating devices and the second in series therewith at or near the source of electricity, an indicator affected by currents traversing the coils, an artificial resistance in circuit with the shuntcoil, and a coil for opposing the effect of said shuntcoil upon said indicator, and a resistancein circuit therewitl1,said resistances being differently affected by currents traversing them.

2. The combination, with a source of electricity,0f two opposing coils, one connected in shunt and the other in series with the workcircuit, an indicator affected by currents traversing the coils, and a second coil, also in shunt upon the series coil and opposing in its effects the action of the first named shunt-coil, and artificial resistances in the respective circuits of the shunt-coils, which are differently affected by currents traversing them.

3. The combination of two opposing coils, an armature acted upon thereby, two branch circuits including said coils, respectively, a carbon resistance in one circuit and a metallic resistance in the other circuit,and a third coil opposing the coil connected incircuit with the carbon resistance.

4. An electricindicator consisting of two 0pposing coils, a metallic resistance in circuit with one coil, a resistance varying with the quantity of current traversing it in circuit with the second coil, a third coil, and an indicator acted upon by the resultant effects of the OLIVER B. SHALLENBERGER.

Witnesses:

W. D. UPTEGRAFF, GHARLEs A. TERRY. 

